The present invention relates to an electro-optical device using a self-luminous element, a driving circuit and a driving method thereof, and an electronic apparatus using the electro-optical device.
As an image display device taking the place of liquid crystal display devices, a device comprising an organic light emitting diode element (hereinafter, referred to as OLED element) is being noticed. The OLED element is a current-driven self-luminous element, unlike liquid crystal elements which change the amount of light to be transmitted.
In an electro-optical device having the OLED element implemented with an active matrix driving method, a pixel circuit for adjusting the light-emission grayscale level to the OLED element is provided. The setting of the light-emission grayscale level in each pixel circuit is performed by supplying a voltage level or a current level depending on the light-emission grayscale level to the pixel circuit. The method in which the setting of the light-emission grayscale level is performed by the voltage level is called a current-program mode. The pixel circuit in the current-program mode operates to repeat alternately a writing period in which a current depending on the light-emission grayscale level to be supplied from a current generating circuit via a data line is stored and a light emitting period in which the stored current is supplied to the OLED element. The storing of the current level is performed by providing a capacitive element between a gate and a source of a transistor serving as a current source of the OLED element and by storing charges in the capacitive element such that a gate-source voltage of the transistor depends on the current.
Conventionally, as the current-generating circuit which generates the current to the pixel circuit, for example, a construction shown in FIG. 24 of Patent Document 1 may be exemplified. In this drawing, the current-generating circuit is a current-addition D/A converter in which by switching respectively transistors 20a to 20f depending on each of 6-bit digital data (D0 to D5), element currents i1 to i6 are selected, and the selected element current is synthesized to obtain a current lout. Japanese Unexamined Patent Application Publication No. 2003-233347.